Preheat oven to 325F.
Grease a 9x9 metal pan lightly or line with parchment paper.
Melt chocolate in a double boiler over simmering,
but NOT boiling, water. Let cool to room temperature.
Cream the butter until it is fluffy. Add the sugar in thirds,
continuing to beat the mixture until it is light and fluffy.
Add the in thirds, continuing to beat the mixture until
it is light and fluffy. Add the eggs, 1 at a time, beating each in well.
Mix in the melted chocolate. Fold in the flour by hand.
Do not overmix. Fold in the nuts if you are using them.
Pour batter into the prepared pan.
Bake for 22-25 minutes (if you are using a glass pan,
bake 17-20 minutes) or until top is dry and a toothpick
inserted 1 & 1/2 inch from center comes out clean.
Cool completely in the pan before cutting. ENJOY!!!!!